[PATCH 4.9 06/33] btrfs: send: in case of IO error log it

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Dāvis Mosāns <davispuh@gmail.com>

commit 2e7be9db125a0bf940c5d65eb5c40d8700f738b5 upstream.

Currently if we get IO error while doing send then we abort without
logging information about which file caused issue.  So log it to help
with debugging.

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/btrfs/send.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -4675,6 +4675,10 @@ static ssize_t fill_read_buf(struct send
 			lock_page(page);
 			if (!PageUptodate(page)) {
 				unlock_page(page);
+				btrfs_err(fs_info,
+			"send: IO error at offset %llu for inode %llu root %llu",
+					page_offset(page), sctx->cur_ino,
+					sctx->send_root->root_key.objectid);
 				put_page(page);
 				ret = -EIO;
 				break;